Anxiety disorders are the most common psychiatric illnesses in the United States, with a prevalence of nearly 29%.1 These disorders typically are treated with pharmacotherapy, psychotherapy, or a combination of both. Pharmacotherapy for anxiety has evolved considerably during the last 30 years, but medications are not efficacious for or tolerated by all patients. For example, selective serotonin reuptake inhibitors, which are frequently used for treating anxiety, can cause sexual dysfunction,2 weight gain,2 drug interactions,2 coagulopathies,3 and gastrointestinal disturbances.4 Psychotherapeutic techniques, such as cognitive behavioral therapy (CBT) and interpersonal therapy (IPT), are efficacious for mild to moderate anxiety.5-7

In addition to standard pharmacotherapy and psychotherapy, some evidence suggests that complementary therapies, such as yoga, massage, and relaxation techniques, may be beneficial as adjunctive treatments for anxiety. In placebo-controlled trials, several of these complementary therapies have been shown to decrease serum levels of the inflammatory biomarker cortisol. Anxiety is associated with inflammation,8 so therapies that reduce inflammation may help reduce symptoms of anxiety. Here, we describe the results of select positive randomized controlled trials (RCTs) of several complementary interventions for anxiety that might be useful as adjunctive treatments to psychotherapy or pharmacotherapy.

A look at RCTs that measured both anxiety and cortisol

We searched PubMed, Google Scholar, and Scopus to identify RCTs of complementary nonpharmacologic and nonpsychotherapeutic therapies for anxiety published from January 2010 to May 2017. We included only studies that:

Evaluating both STAI scores and cortisol levels is useful because doing so gives insight into both the clinical and biological efficacy of the therapies. Studies were excluded if they employed a pharmacologic agent in addition to the approach being evaluated.

Yoga

Yoga has become increasingly popular in the Western world during the last 2 decades.10 There are a variety of yoga practices; common forms include hatha yoga, power yoga, kripalu yoga, and forrest yoga.11

A study of 92 depressed pregnant women monitored the effects of 20 minutes of yoga once a week for 12 weeks.12 Half of the women were randomly assigned to the yoga intervention, which consisted of standing, kneeling, and seated poses, and half were assigned to a social support discussion group. After 12 weeks, both groups had significant decreases in STAI scores. Both groups also had statistically significant decreases in salivary cortisol levels immediately after each session.12

Hatha yoga consists of a combination of postural exercises, breathing techniques, relaxation, and meditation. In a 12-week study of 88 postmenopausal women, those who practiced hatha yoga for 75 minutes a day had significantly lower STAI scores compared with women who exercised for 75 minutes a day and those who performed no physical activity.13